Efficiency of optical parametric oscillation in the constant intensity approximation

A theory of optical parametric amplifiers and oscillators is developed in the constant intensity approximation taking into account the reaction on the pump wave phase. Optimization of various parameters such as the length of the nonlinear medium, the reflection coefficient of the mirrors, the wave mismatch, and the intensities of the pump and idler waves was studied to maximize the signal wave gain. Analytic expressions were derived for the resonance phase condition and for the optimal reflection coefficient of the mirrors reflecting the amplified wave.